SEOUL - Singapore Airlines has tweaked its in-flight seatbelt sign policies and altered at least one flight route after a turbulence incident this week killed one person and left dozens critically injured, according to the airline and flight data.

The airline is adopting a more cautious approach to turbulence, including not serving hot drinks or meals when the seatbelt sign is on, it said in a statement to Singapore broadcaster Channel News Asia.

"SIA will continue to review our processes, as the safety of our passengers and crew is of utmost importance," it said.

The daily London to Singapore route SQ321 has completed two flights since the incident and not flown over the part of Myanmar where the sudden turbulence occurred about 3 hours before scheduled landing. The flight time is about the same, tracking data show

The airline did not respond to a Reuters request for comment.

The SQ321 London-Singapore flight on a Boeing 777-300ER plane carrying 211 passengers and 18 crew diverted to Bangkok for an emergency landing on Tuesday after the plane was buffeted by turbulence that flung passengers and crew around the cabin, slamming some into the ceiling.

The daily London to Singapore route SQ321 has completed two flights since the incident and not flown over the part of Myanmar where the sudden turbulence occurred about 3 hours before scheduled landing. The flight time is about the same, tracking data show.

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They flew instead over the Bay of Bengal and Andaman Sea, route data from flight tracker FlightRadar 24 shows.

Singapore Airlines has said the plane on Tuesday encountered sudden extreme turbulence. A 73-year-old British passenger died of a suspected heart attack.

Photographs from inside the plane showed gashes in the overhead cabin panels, oxygen masks and panels hanging from the ceiling and luggage strewn around. A passenger said some people's heads had slammed into the lights above the seats and broken the panels.

As of late Thursday, 48 passengers and two crew members were hospitalized in Bangkok; 19 others were still in Bangkok, the airline said.

Twenty of the 48 remained in intensive care, an official at Bangkok's Samitivej Srinakarin Hospital said on Thursday, adding that the injured had a mix of spinal cord, brain and skull injuries.

READ MORE: After Singapore Airlines turbulence mishap, flight crews urge buckling up

Singapore Airlines, which is widely recognized as one of the world's leading airlines and is seen as a benchmark for much of the industry, has not had any major incidents in recent years.

Turbulence

A spate of turbulence reports has triggered a debate over whether climate change may be causing an uptick. A report from the University of Reading last year suggested turbulence could worsen with climate change.

Paul Williams, one of the authors, has said more research is needed to understand the impact of climate change on air turbulence.

Technological advances have helped limit the number of turbulence-related fatalities, which have significantly decreased in the past 20 years.

I think this incident will prompt airlines, whether it's an official mandate or not. But airlines saying "we recommend you keep your seatbelt fastened while seated", should be saying it is mandatory to keep your seatbelt done up.

Geoffrey Thomas, Airlineratings.com editor-in-chief

Airlineratings.com editor-in-chief Geoffrey Thomas said some airlines may change their policy on wearing seatbelts as a result of the incident.

Airlines are required by law to switch on the seatbelt sign during takeoff and landing, but carriers have their own procedures to deal with midair turbulence.

"I think this incident will prompt airlines, whether it's an official mandate or not. But airlines saying ‘we recommend you keep your seatbelt fastened while seated’, should be saying it is mandatory to keep your seatbelt done up,” Thomas said.

Flight data

On Friday, Singapore Transport Minister Chee Hong Tat said the city-state's investigators have obtained data from the cockpit voice recorder and flight data recorder.

"We have a team that went to Bangkok and they have obtained the data from the cockpit voice recorder and flight data recorder," the minister said in a statement.

"They are going through the data from these two recorders now to be able to ascertain what happened during those moments."

The ministry is awaiting findings of the investigation by the Transport Safety Investigation Bureau (TSIB) Singapore, he said.